add task module

backend/modules/task/views/default/index.php

@@ -0,0 +1,12 @@
+<div class="task-default-index">
+    <h1><?= $this->context->action->uniqueId ?></h1>
+    <p>
+        This is the view content for action "<?= $this->context->action->id ?>".
+        The action belongs to the controller "<?= get_class($this->context) ?>"
+        in the "<?= $this->context->module->id ?>" module.
+    </p>
+    <p>
+        You may customize this page by editing the following file:<br>
+        <code><?= __FILE__ ?></code>
+    </p>
+</div>